The Type GFR..F3F4 is a self-contained and sealed roller-type freewheel. It is supported by two 160-series bearings. The unit must be lubricated with oil before being used.
A GFR base module is employed by the model in its design. The F3 cover is used as a torque arm and has an integrated stop bolt. The stop bolt is intended to go into a slot in a fixed part of the equipment. The torque arm and the bearings must not be stressed before usage. The F4 cover is used to close the unit and is equipped with three screws for oil filling, draining, and leveling. Its shaft and end plate must be sealed to prevent oil leakage in the keyway.